Topic 5: Homeostasis and Response

    Cards (118)

    • What is the definition of homeostasis?
      Regulation of internal conditions of a cell
    • Why is homeostasis important for organisms?
      To maintain optimum conditions for enzyme action
    • Name three conditions regulated in the human body.
      Blood glucose levels, body temperature, water levels
    • What are the components of automatic control systems in homeostasis?
      1. Receptor cells (detect stimulus)
      2. Coordination centre (processes information)
      3. Effectors (bring about responses)
    • What role does the coordination centre play in homeostasis?
      It receives and processes information from receptors
    • What are effectors in the context of homeostasis?
      Muscles or glands that bring about responses
    • How do automatic control systems respond to changes?
      They may involve nervous or hormonal responses
    • Why is the misconception that "an effector detects a stimulus" incorrect?
      An effector carries out a response, not detection
    • Why should body temperature not increase too much?
      Enzymes become denatured at high temperatures
    • What happens when blood pressure becomes too high?
      Receptors detect high blood pressure and signal coordination centre
    • What is the first step in the negative feedback mechanism for high blood pressure?
      Receptors detect that blood pressure is too high
    • What is the role of the coordination centre in blood pressure regulation?
      It processes information and organizes a response
    • What do effectors do in response to high blood pressure?
      They produce a response to decrease blood pressure
    • What is the function of the nervous system?
      To react to changes in surroundings
    • Describe the overall structure of the human nervous system.
      1. Central nervous system (CNS) - brain & spinal cord
      2. Other nerves - bundles of neurones
    • How does information pass along neurones?
      As electrical impulses
    • What is a synapse?
      Small gap between two neurones
    • How does information pass across a synapse?
      A chemical is released and diffuses across
    • What are the steps in a nervous system response to a stimulus?
      Receptor, sensory neurone, CNS, motor neurone, effector
    • What is a reflex action?
      Automatic and rapid response not involving conscious brain
    • Why are reflex actions important?
      They help minimize damage to the body
    • What is a reflex arc?
      Pathway of a reflex action through the nervous system
    • What is the role of the relay neurone in a reflex arc?
      Passes impulses from sensory to motor neurone
    • What is the misconception about how information travels along neurones?
      It travels as electrical impulses, not signals
    • Why does a conscious action take longer than a reflex action?
      The impulse has to travel to the brain and back
    • How is information detected when touching a hot object?
      Temperature receptors in skin detect the stimulus
    • What is the ruler-drop test used for?
      To measure human reaction time
    • Describe the method for the ruler-drop test.
      1. Person A holds ruler above person B's hand
      2. Ruler dropped without warning, person B catches it
      3. Record distance caught, convert to time
    • Why is it important to control variables in the ruler-drop test?
      To ensure valid and reliable results
    • How can caffeine affect reaction time?
      It blocks adenosine receptors, increasing impulses
    • Why do students wait 15 minutes after drinking coffee before testing reaction time?
      To allow caffeine to be absorbed into the body
    • Why is using a computer to measure reaction time more valid?
      It provides more precise timing measurements
    • What are the functions of the cerebral cortex, cerebellum, and medulla?
      • Cerebral cortex: Consciousness, intelligence, memory, language
      • Cerebellum: Muscle coordination, movement, balance
      • Medulla: Regulates unconscious activities (heartbeat, breathing)
    • How do neuroscientists map brain functions?
      By studying patients with brain damage
    • What is a challenge in investigating brain function?
      The brain is delicate and complex
    • What is the misconception about the cerebellum and memory?
      The cerebral cortex is responsible for memory
    • What happens if a person has a head injury and staggers while walking?
      The cerebellum is likely damaged
    • How can fMRI scanners help in brain damage assessment?
      They show active/inactive brain regions during tasks
    • What are the receptors in the eye sensitive to?
      Light intensity and colour
    • Describe the structure and function of the retina and optic nerve.
      • Retina: Contains receptors sensitive to light intensity/colour
      • Optic nerve: Carries electrical impulses from retina to brain
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